1. Field of the Invention
In the United States, industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Clearly, industrial drying is a significant energy and monetary expense for the United States industrial complex. The present invention relates to the drying of granular, slurry, or liquid feeds in a novel drying vessel utilizing superheated steam as the drying medium.
2. Description of the Prior Art
Thermal drying of granular, slurry or liquid feeds has been accomplished in prior art devices through the use of devices which employ elements which remove water from the feedstock via evaporation. There are however, inherent risks in such processes in that such processes have explosive hazards associated therewith due to dust. Additionally, inherent is such devices is the need for large energy requirements which are obtained at a cost to our environment.
Attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, a large amount of heat of evaporation from the evaporated water cannot be recovered and/or in some way utilized.